a. Field of the Invention
The present invention relates generally to a data collection and analysis system for facilitating intelligent diagnostics and failure prevention.
b. Description of the Related Art
Dynamic systems such as transportation-systems and in particular vehicles are widely employed. In commercial settings, vehicles such as automobiles, trucks, buses, etc. are relied upon to operate with minimum maintenance over extended periods of time. For many businesses, a fleet of vehicles must be maintained and their usage coordinated for safe and efficient utilization of vehicle resources. For these businesses, downtime, and the random nature of it, is a significant concern. Likewise, passenger vehicles are also widely employed and, for consumers, these vehicles must be maintained to ensure driver and passenger safety.
Notably, such vehicles typically have a plurality of costly subsystems. In most vehicles, at least a small percentage of vehicle subsystems including lubrication, brakes, etc., are prone to failure at any time and, therefore, periodically require maintenance. Typically, maintenance is performed on a schedule (e.g., change the oil every 3,000 miles) without regard to the actual health status of the associated subsystem.
In addition to normal aging and use, failures due to poor or no maintenance and improper operation of the vehicle (e.g., xe2x80x9cridingxe2x80x9d the brakes, aggressive driving, etc.) take a significant toll on the vehicles, thus resulting in significant expense and logistical problems for the owner. Moreover, this problem is exacerbated when maintaining a large number of vehicles. As a result, a convenient yet inexpensive failure prediction system is desired.
Depending on the application, the failure of a vehicle in service can lead to overall system or process downtime, inconvenience, and potentially, the creation of a hazardous situation. Thus, it is desirable to monitor and diagnose potential failure or faults in these vehicle subsystems early in order to avoid such problems. Absent intelligent monitoring of the subsystems, these problems can have an insidious effect when a problem, although relatively minor and correctable if detected early, goes undetected and yields a set of circumstances that becomes more serious the longer the problem goes undetected. For example, steering and more general torque problems may not become apparent until irreversible damage has occurred. Likewise, problems due to inadequate lubrication, contamination or a multitude of other causes may not become apparent until the subsystems are damaged or a catastrophe occurs.
In order to reduce the probability of failure, preventive maintenance programs have been implemented in which vehicles are periodically serviced and routine maintenance is performed, while data regarding the general health and status of the vehicle is collected and recorded. By routinely conducting such preventive maintenance, vehicle subsystems are serviced whether or not such service is needed. This process results in vehicle downtime, significant costs and requires coordination of scheduled maintenance. Again, such problems are exacerbated when a plurality of vehicles, e.g., a fleet of commercial trucks, must be maintained. When maintenance is performed even though the actual health of the vehicle dictates that it is not necessary, overall process or system costs must be absorbed by the owner of the vehicles.
Moreover, often times no diagnostic or prognostic tests are performed as part of these routine service checks, relying instead on the driver or a maintenance specialist to detect fault conditions (e.g., via visual inspection, out-of-the-ordinary noises, etc.). Notwithstanding routine maintenance, often times unanticipated problems go unnoticed and ultimately develop into serious subsystem failures. Clearly, such a system is inefficient and, more importantly, places many of these vehicles at high risk of serious subsystem failure while in operation. This is a hazardous situation that should be avoided if at all way possible. Some on-board vehicle computer systems exist, but these systems are typically limited in scope and do not have the capability to analyze a comprehensive range of specific vehicle components (e.g., steering, brakes, fuel, etc.). In addition, no known system can efficiently detect early subsystem faults and failures or predict the time to failure. For example, some engine crankcase oil monitoring systems integrate time and temperature to determine if the oil needs to be replaced, but do not consider the effect of lubricant contaminants or multiple short cold running trips that never get the engine up to operating temperature.
Therefore, the field of vehicle diagnostics and maintenance systems is in need of an intelligent system that gathers real-time information relating to the health of a plurality specific vehicle subsystems to determine when maintenance is or will be required.
The present invention overcomes the limitations of prior vehicle diagnostic systems by providing a system of data collection and diagnostic/prognostic modules that collect data pertaining to vehicle subsystems and process the data to facilitate determining a health state of the individual subsystems, as well as a health state of the overall vehicle. The invention also can be utilized to predict trends in performance of the vehicle, thus affording the present system the ability to accurately and reliably predict when the next vehicle component/subsystem will fail. The system preferably includes a master diagnostics unit that is swappable and modular for rapid diagnosis of subsystem problems and efficient storage of vehicle maintenance records. These system features minimize vehicle downtime and maintenance costs without compromising vehicle performance and safety. In addition, by combining the results of subsystem analysis into an overall system (vehicle) model, the accuracy of the health assessment of individual subsystems may be improved. Also, system-level faults such as subsystem interaction problems and specific faults not previously defined may be detected.
More particularly, the subsystem modules are operatively coupled to components within each of the subsystems via an associated set of sensors. The sensors are positioned at suitable points within the subsystems to collect the desired data. The sensors are preferably intelligent sensors that are adaptable to different operating environments, such as those described hereinafter. The subsystem modules are, in turn, electrically coupled to a master diagnostic module that performs overall system health assessment. Because many of the sensors are placed substantially permanently within the components of corresponding subsystems, as are the subsystem modules, the master diagnostic module, in one preferred embodiment, can be quickly removed or inserted into a docking station mounted on the vehicle without having to worry about proper positioning of the sensors or their associated subsystem modules.
In operation, data is preferably collected, processed and stored by the individual subsystem modules, which themselves are capable of processing and diagnosing maintenance concerns in generating subsystem health assessment signals. The master diagnostics module receives the subsystem health assessment signals and, in response, generates and stores in a memory an overall vehicle health assessment. This memory is preferably sufficient to store a substantial amount of raw and/or processed data. As a result, the master diagnostics module may be employed to gather data for extended periods of time, for example, several weeks, several months or several years. Data collection for extended periods of time affords improved accuracy and machine diagnosis as well as substantially facilitating trend analysis of machine performance and failure prediction.
Furthermore, because the sensors are strategically disposed on or within the vehicle subsystems, and more particularly, the subsystem components, as compared to placing the sensors within the modules, the present invention provides for accurate and reliable data from which to base subsystem and overall vehicle diagnostics and trending.
Overall, the present invention permits a substantial portion of vehicle subsystem and overall vehicle diagnostic processing and analyses to be performed locally, i.e., on board. As a result, in at least one preferred embodiment, the amount of data that is sent to a remote computer for additional processing is minimized, thus reducing bandwidth and/or transmission time requirements for data transmission.
According to one aspect of the invention, a vehicle diagnostic system for collection of data relating to a plurality of subsystems of a vehicle includes a plurality of sensors, each sensor gathering data and generating a data signal indicative of the health of a corresponding one of the subsystems. In addition, the vehicle diagnostic system includes a plurality of subsystem modules each electrically coupled to corresponding ones of the sensors for generating a subsystem health assessment signal in response to corresponding ones of the data signals. The system further includes a master diagnostics module electrically coupled to the subsystem modules to generate an overall vehicle health signal. It may also use the inherent coupling of vehicle subsystems to further establish the health assessment of individual subsystems.
According to another aspect of the invention, a vehicle diagnostics/prognostics system for collecting and processing data relating to a plurality of subsystems of a vehicle includes a plurality of subsystem modules for receiving health assessment information associated with each of the subsystems and generating corresponding subsystem health signals based on the health assessment information. In addition, the system includes a master diagnostics module electrically coupled to the subsystem modules and including a memory having a health assessment model embedded in the memory, the master diagnostics module for generating a vehicle health assessment based on the health assessment model and in response to the subsystem health signals.
According to another aspect of the invention, the system includes a central terminal adapted to be communicably coupled to the master diagnostic module to facilitate further processing of the subsystem and overall vehicle health signals for generating maintenance schedules and trend analyses.
According to a still further aspect of the invention, the master diagnostics module is a plug-in module that is communicably coupled to the central terminal via a docking station situated at a location remote from the vehicle. Preferably, the central terminal includes a host computer to facilitate further diagnostics and trending processing.
According to another aspect of the invention, the master diagnostics module is communicably coupled to the central terminal via a wireless communications interface such as radio, digital cellular , paging network, etc.
According to yet another aspect of the invention, a method of determining when a vehicle requires maintenance includes the step of using a plurality of sensors to gather data indicative of the health of corresponding ones of a plurality of subsystems, and to generate corresponding data signals based on the health data. Further, the method includes the step of providing a plurality of subsystem modules each associated with a corresponding ones of the subsystems, each of the subsystem modules being electrically coupled to a corresponding one of the sensors. Next, the method includes the steps of generating, with the subsystem modules, subsystem health signals in response to corresponding ones of the data signals, providing a master diagnostics module electrically coupled to the subsystem modules, and generating, with the master diagnostics module and in response to the subsystem health signals, a vehicle health signal.
These and other objects, features and advantages of the present invention will be better appreciated and understood when considered in conjunction with the following description and accompanying drawings. It should be understood that the following description indicates one or more preferred embodiments of the present invention, but is given only to illustrate and not to limit the invention. Many changes and modifications may be made within the scope of the present invention without departing from the spirit thereof, and the invention includes all such modifications.